Counter and display systems



Feb. '27, 1962 R- W- STUART JR 3,022,944

COUNTER AND DISPLAY SYSTEMS Filed Nov. 12, 1958 5 Sheets-Sheet 1lINVENTOR. Rom:r= TvlfsTuARTml ATTORNE vs Feb. 27, 1962 Filed Nov. 12.1958 R. W. STUART, JR

COUNTER AND DISPLAY SYSTEMS 5 Sheets-Sheet 2 IOOV BY. Mja.

AT TORNEYS Feb. 27, 1962 Filed Nov. 12, 1958 R. W. STUART, JR

COUNTER AND DISPLAY SYSTEMS 5 Sheets-Sheet 3 INVENTOR. Ro BERTMSTUAT BY:2. WZ,

ATTORN EYS Filed NOV. 12, 1958 R. W. STUART, JR

COUNTER AND DISPLAY SYSTEMS IOOV.

i l l5) I 80V.

4 20V. 60V. 60V. I l

2R 2R 2R P OV IZOV. OV FIG 4 5 Sheets-Sheet 4 Sov.

P 80V. ov.

INVENTOR. ROBERTVISTUARTSR4 ATTORNEYS Feb. 27, 1962 Filed Nov. 12. 1958R. w. STUART, JR COUNTER AND DISPLAY SYSTEMS BY l / ATTORNEYS though itis to'be vunderstood that the invention is of broader utility, as willbe evidentfrom 'the subsequent description. In such counting apparatus,successive serial` connected, Yswitching vcircuits, are customarilyemployed, such as iiipflop`or multivibrator 'eleotronftube transistor orother relay stagesv that are 'operable to assume either a first state,designated by fO, or a second state, designated by the numeral 1. Forpurposes of convention, the"0 state may represent the conditionwhere'the right-hand -tubeof the pair of flip-liep tubes 'is conductfing and the left-*handtube is c ut oi, while the state 'may representthe reverse. condition. The `counter is providedwith an appropriatefeedback system ior obtaining a desired binary sequence `of count.' Withfour such switchng stages, for example, the following binarysequence'rnay be obtanedas successive impulses are applied to thecounter:

` Y State of switching stage Number of input impulse ,lst 2nd 3rd 4th io o o i1 1 0 0 0 o 1 o o 1 1 o .0 o 1 1 n 1 1 1 u c 0 1 1 1 o I 1 1 o 11 1 1 1 .1 1 o o 0 o Counter circuits for producing such operation andillurninating successive display bulbs, lamps orother indicators as thesystem-'counts from through9 aredescribed,- .for example, in UnitedStates Letters Patent No. 2,521,788; issued September 12, 1956, to IgorE. Grosdof.v Unfortunately, however, while such a circuit can reliablyoperate the-display bulbs without ambiguity, the feedback s 3,c2z,944Patented Fels. 27, lgz

rice

2 which is preferred "for thev purpose of thel present invention, is thefollowing;

state of switching stage It'is'inherentlypossible,howeven-in a decadecounter employing th.- above binary sequence for oneV or more of ,theindicator bulbs-to tire erroneously, as is later more fully explained.'vc This, of course,'is a most. undesirable condition. While it may beremedied by increasing the power-supply requirements, such byincreasingY the 'plateswing ,of the-'switchingLtube stages from, say,120 volts to'. 180 volts, such `a solution is 'clearly costly andundesirable: Sir'nilarly, `networks employing diodes lmay be employedtoprevent such spurious operation, but such networks again are relativelyvexpensive and thus also do not provide a satisfactory solution from thecommercial point of view.

It is, accordingly, 'an object of Vthe present invention to overcomethesedi'sadvantages'oi the -prior art'and to provide a novel countingand indicating system, operable reliably a't both' low and high countingspeeds,` and pro# videdwith simple 'and inexpensive means for inhibitingverroneous operation of the counting indicator devices. In summary, this.end is attained with the aid of an inhibiting network comprising atbreshold-voltage-operated non-f linear device, preferably-atwo-electrode neon -tube and theflilte'.y

A-further-object is to provide anew and improved counting andindicatingsystem.

)Otherand further objects will be explained hereinafter andwill'be moreparticularly pointedout-in the appended claims.

The invention will nowbe describedin'connection with the accompanyingdrawing. v v

FIG. 1 of which is a circuit diagram of a decade counter constructed inaccordance with a preferred embodiment-of theV invention, witlrtliedetails ofthe switching s circuitsillustratediny block-diagram form inview ofthe system required Vto produce theabove sequence is subject fact'that theyare well known and in order not to comf plicateV the drawingso as to detract from the novel featuresofthepresent invention; and l ss FIGS.A 2 throughlS are similar diagrams'kof thesupper orindicatorpart'ofrthesystemof FIG. 1, illustrating the operation .for successivelyadvanced counting conditions.

Associatedgwithjthe1st, 2nd, 3rd and 4th switching stages "of FIG. 1.,`adapted topr'odu'ce the second-mentioned binary sequence, nabove, areten indicators, such as Atworlelectro'cle neon bulbs or lamps numberedti, l, 2, 3, 4, l5,127, Sand?. 'lfhefoutput circuit of eaclioi 'the pairof ip-iiops. or other switching relays'y of the lst, 21nd,r B rdand{itlifswitching-v stages'fis connected `through preferably aesistorfload vtothe vpositive terminal Ebb of minals P1 and P2 of the1st Switching Stage and the output terminal P8 of the 4th SwitchingStage are shown connected to Ebb through pairs of equal resistors, eachof value RL/z. The output terminals P3, P4 of the 2nd Switching Stage;P5, P6, of the 3rd Switching Stage; and P7, of the 4th Switching Stageare all connected through resistors of value RL to the power-supplyterminal Ebb. The successive switching stages are serially connected inconventional fashion, as is'illustrated by the connections 12, 14 and 16between the output terminals P2, P4 and P6 and the respective inputterminals I2, I3 and I4 of the 2nd, 3rd and 4th switching stages. Theimpulses to be counted and indicated or displayed may be ted to theinput terminals, represented at I1, of the 1st Switching Stage, and thecarry output of the decade counter may be connected to the outputterminal Ps of the 4th Switching Stage. The required feedback path forproducing the desired binary sequence is shown labelled Feedback andconnected from the output terminal Pq of the 4th Switching Stage to thefurther input terminals I2 and I3 of 'the 2nd and 3rd switching stages,respectively, associated with the right-hand relays ot the pairs ofrelays associated with each switching stage, as is well-known.

The upper terminals of indicator or display devices 0, 2, 4, 6 and 8 areconnected to the common conductor 13 and the upper terminals of the oddindicators 1, 3, 5, 7 and 9 are similarly connected to a commonconductor 15. Each of the common conductors 13 and 15 connects through aresistance of value R (such as', for example, approximately 200 kilohms)and respective conductors 13 and 15 to the rnid-point terminals P1' andP2' of the output-circuit loads Rm: of the lst Switching Stage. Thelower terminal of each of the indicators 0, 1, 2, 3, 4, 5, 6 and 7 isconnected to a resistor of value 2R (such as 400 kilohms) and the lowerterminals of the pairs of indicators 1, 2 3, 4 5, 6 7 and 8 9* areconnected together by respective conductors 17, 19, 21, 23 and 25. 'Theresistors 2R connected to the lower terminals of indicators 0 and 4 are,in turn, connected to the righthand output terminal P4 of the 2ndSwitching Stage by conductor 18. A similar connection is effected by conductor 20 to the right-hand output terminal P6 of the 3rd SwitchingStage from the resistors 2R associated with indicators land 3. Theresistors 2R connected to the lower terminals of indicators 2 and 6 alsoconnect by conductor 22 to the left-hand outputterminal P3 of the 2ndSwitching Stage. The left-hand output terminal P5 of the 3rd SwitchingStage similarly connects by conductor 24 to the resistors 2R associatedwith the indicators and 7. The conductor Z5, interconnecting the lowerterminals of indicators 8 and 9 is, in the same manner, connectedthrough a common resistor of value R by conductor 26 to the left-handoutput terminal Pq of the 4th Switching Stage.

In order to facilitate description of the operation of the preferredcircuit of the present invention, typical voltage values are placed atappropriate locations in the circuit upon the assumption that, forexample, electrontube flip-flop switching circuits are employed, with anoff tube plate voltage 40 volts below Ebb and an on" tube plate voltage160 volts below Ebb. These voltage values are expressed as numeralsfollowed by the symbol V., meaning volts; thus, for example, the upperterminals of the resistors R, connected between respective conductors 1313 and 1S 15, are shown maintained at voltages 140V. and 80V., meaningonehundred forty volts and eighty volts, respectively. These voltages,for convenience, have been referred to the on plate voltage of theswitching stages, this voltage being arbitrarily assigned as ground orzero volts (OV.). The beforementioned -illustrative 200K value ofresistance R is suitable for use with neon-bulbindicators for a currentot the order of 0.2 milliampere. The shading of indicators 0, 2, 4, 6and 8 in FIGS. 1 through 5, furthermore, 'represents` the tiring ofthose indicator or display devices,

4 it being understood that similar tiring of indicators 1, 3, 5, 7 and 9will occur with the voltages atterminals Pp and P2' reversed.

The novel inhibitor network of the present invention is shown connectedbetween indicators 6 and 7. It comprises a threshold-voltage operatedbi-laterally conducting neon or similar two-electrode gaseous-dischargetube or bulb N, though, as will be evident from the description, otherdevices having similar properties may be used. The upper electrode El ofthe neon tube or similar device N, FIG. 1, is connected to conductor 23;and the lower electrode E2 connects preferably through a resistance ofvalue R/S and by a conductor 23 to the midpoint P8 between theoutput-circuit resistors RL/Z of the right-hand relay of the 4thSwitching Stage. As is evident from FIGS. l thru 4 of the drawings, theinhibitor device N is inoperative for the states where the impulsesnumbered 0, 2, 4 and 6 are involved., and it may similarly be shown tobe inoperative for impulses numbers l. 3, 5 and T, as well. For theimpulse-number states 0 through 7, therefore, the proper indicator bulborlamp is fired in response to the corresponding impulse number or countand all other indicator bulbs, las shown by the voltage values assignedin FIGS. 1 through 4, are held with a potential across them of no morethan 40 volts. 'I'his is insuflicient voltage to fire the otherindicators so that unambiguous firing will occur.Y For NE-Z type neonbulbs, for example, the bulbs will lire at approximately volts, assumingappropriate ambient light energy or other stimulus is present, and willconduct with 60 volts applied across the bulb, so that the not-more-thanl0-volt condition reliably prevents any erroneous operation.

In FIG. 5, the situation is diterent. The lowered voltage at outputterminal P7 serves to tire the indicator or display device 8 correctlyin the intended manner, as shown. In the absence of the inhibitingcircuit N-R/3, however, the common junction 23 of indicators 6 and 7will also fall in voltage value, causing indicator 6 to lireerroneously. Similarly, indicator 7 will erroneously tire when indicator9 is tired. With the inhibiting circuit of the present invention, sucherroneous operation is obviated. The fall in voltage of the 6 7 bulbjunction 23, combined with the voltage rise of output terminal P8. willcause the inhibit device N to re. The current through N is designed tobe sulicient (preferably 3/2 of the normal indicator bulb current forthe relative resistance values shown in this case) to hold the junction23 of the 6 7 indicators high enough (60 volts), so that indicator 6cannot lire because of the insutlcient voltage across it (40 volts). Theinhibitor N also similarly operates on state 9 to prevent erroneoustiring of the indicator 7.

The present invention, therefore, with the aid of an inhibitor circuitcomprising reliable and inexpensive threshold-voltage operatednon-linear neon or similar devices, such as the before mentioned NE-2type bulb, thus insures against erroneous indicator iiring andcompletely overcomes all of the before-mentioned disadvantages of theprior art.

The extension of the neon bulb inhibiting system described herein canlead to further improvements in decade counter indicator systems. Inparticular, if a suiiicient, number of inhibiting neon bulbs are used,it is possible to reduce the voltage swing requirements of theflip-tlops to 60 volts instead of the 120 volts required with oneinhibitor circuit, or the volts required with no inhibitor circuit.

Further modifications will occur to those skilled in the art and allsuch are considered to fall within the spirit and scope of the inventionas defined in the appended claims.

What is claimed is: l

l. An electric system having, in combination, a plurality of switchingcircuits for counting successive im, pulses, an indicator for displayingthe resulting count of anemona switching circuits, and theotherwithxaxthirdtswitching;

circuit through electric-circuit connecting means;

2. An electric system having, in combination, a plu rality of switchingcircuits .for counting successive impulses', an indicator for displayingthe resulting .count .of` `the switching circuits, andV a couplingcircuit intercom-- necting the.`switching circuits and the indicatorandcom-` prising a two-electrode gaseous-discharge-device one ter-1minalof which is connected witlieach of two switching. circuits, and theother with a. third-switching circuit through electric-circuitconnecting means:

3; An electric system having, incombination,` aplurality of -switchingcircuits-.for counting'.v successive impulses, an indicator. fordisplaying the Yresulting countofr the switching' circuits, and acoupling circuit-intercom:

necting the switching circuits-and the indicator and coinprising atwo-electrodeA neon-,tube device .oriegtcrrninalof-` which' isconnectedwith each of tw'o switching' circuits; andthe other with a thirdvswitching.circuit throughelectiic-circuit connecting-means.

4. An electric system having, in combination, a plurality of switchingcircuits for counting successive impulses, and indicator comprisingY apluralityof display devices for registering successive-countingsequences of the switching circuits, one of a pair ofthedisplay'device's being normally undesirably, operated vuponthedisplay operation of the other of the said pair in response to thecounting-actionof the switching circuits; and athresholdvoltage-operated non-linear device connected in circuit -withthe said one display device for inhibiting its operafio atthetimaofihesaid. display Operation of :the Said other f thedisplavdevices 5. An electric system having, in combination, a plurality ofswitching circuits for counting successive impulses, an indicatorcomprising a plurality of `display devices for registering successivelcounting-sequences vof the switching circuits, one of a pair of thedisplay devices being normally undesirably operated upon the displayoperation of the other of the said pair in response tothe countingaction of the switching circuits, and a thresholdvoltage-operatednon-linear gaseous-discharge device connected in circuit with the saidone display device for inhibiting its operation at the time of the saiddisplay operation of the said other of the display devices.

6. An electric system having, in combination, a plurality of switchingcircuits for counting successive impulses, an indicator comprising aplurality of display devices for registering successive countingsequences of the switching circuits, one of a pair of .the displaydevices being normally undesirably operated upon the display operationof the other of the said pair in response to the counting action of theswitching circuits, and a threshold-voltage-operated neon tube connectedin circuit with the said one display device for inhibiting its operationat the time of the said display operation of the said other of thedisplay devices.

7. An electric system having, in combination, a plurality of switchingcircuits -for counting successive impulses, an indicator comprising aplurality of thresholdvoltage-operated display devices for registeringsuccessive counting sequences of the switching circuits, one of a pairof the display devices having a voltage in excess of its thresholdvoltage normally undesirably applied thereto upon application ofoperating voltage in excess of the threshold voltage to the other of thesaid pair in response to the counting action of the switching circuits,and a threshold-voltage-operated non-linear device connected in circuitwith the said one display device and adapted to operate upon operationof the said other of the display devices to maintain the voltage appliedto the said one display device below the threshold voltage,

thereby to inhibit-the-operationoi the said--one-displayv dev-iceuponthe ,displayfvoperation ofthe-said other of;

the display devices. p y

8:, An electric :system having, in combination, a p lurality ofswitchinggcircuitsgifor counting Vsuccessive im-l pulses, anindicato;comprising-.aplurality(ofr thresholdvoltage-operated displaydevices for registering successive counting sequences oitlie switchingcircuits, one of a pair of the display devices,l having a voltage inexcess of its threshold voltage normally undesirably applied i theretoupon application of operating voltage in excess of the thresholdvoltages to the other of the said pair in response to the countingaction of the switching circuits, and a Ithreshold-voltage-operated neontube connected in circuit with the said one display device and adaptedto operate upon operation ofjthe` said other of the display devices tomaintain the voltage applied to the said one display-devicebelow thethreshold voltasesthereby, to inhibitfthe operation of tii'esaid onedisplay,device,ii'pofnI the display operationof the said other" ofkthe'dis'play 79; An 'electric system having', in combination, aiplurality. fipswitching circuitsl for counting vsuccessive pulses` anindicator A.comprising a plurality of display devicesy for` registeringvsuccessive countingY sequences of the switching circuits, each of twokofgthe display', devices being normally undesirably operatedrespectively vupon' the displayV operation ofeachoftwoother ofthedisplay` devices in response to the counting action of the switch'- ingcircuits, and a threshold-voltage-operated non-linear device connectedincircuit'with the said iirstmamed two display devices forVinhibiting,their operation'up'on the said display operation of thelsaid other two lof the Idisplay devices.

l0. An electric system having, in combination, a plurality of switchingcircuits `fer counting successive impulses, an indicator comprising aplurality of display devices for registering successive countingsequences of the switching circuits, each of two of the display devicesbeing normally undesirabl'yjperated -respectively upon the displayoperation of each' f two other of the display devices in response to thecounting action of the switching circuits, and athreshold-voltage-operated non-linear gaseous-discharge device connectedin circuit with the said rst-named two display devices for inhibitingtheir operation upon the said display operation of the said other two ofthe display devices.

l1. An electric system having, in combination, a plurality of switchingcircuits for counting `successive impulses, an indicator comprising aplurality of display devices for registering successive countingsequences of the switching circuits, each of two of the display devicesbeing normally undesirably operated respectively upon the displayoperation of each of two other of the display devices in response to thecounting action ofthe switching circuits, and athreshold-voltage-operated neon tube connected in circuit with the saidfirst-named two display devices for inhibiting their operation upon thesaid display operation of the said other two of the display devices.

l2. An electric system having, in combination, a plurality of switchingcircuits for counting successive impulses, an indicator comprising aplurality of thresholdvoltage-operated display devices for registeringsuccessive counting sequences of the switching circuits, each of two ofthe display devices having a voltage in excess of the threshold voltagenormally undesirably applied thereto upon application of operatingvoltage respectively to each of two other of the display devices inresponse to the counting action of the switching circuits, and athresholdvoltage-operated non-linear device connected in circuit withthe said first-named two display devices and adapted to operate uponoperation of each of the said other two of the display devices tomaintain the voltage applied to the respective display devices of thefirst-named two display devices below the threshold voltage, thereby toinhibit the operation of the first-named two display devices upon thedisplay operation of the said other two of the display devices.

13. An electric system having, in combination, four serially connectedbinary switching circuits for counting successive decades of impulses inthe sequence:

an indicator comprising a decadecf display devices for registeringsuccessive counting sequences of the switching circuits from zerothrough nine, the sixth and seventh display devices of the decade ofdisplay devices being nor mally undesirably operated respectively uponthe display operation of the eighth and ninth display. devices inresponse to the counting action of the switching circuits, and athreshold-voltage-operatedY non-linear device connected in circuit withthe said sixth and seventh display device for inhibiting their operationupon the said display operation lrespectively of the eighth and ninthdisplay devices.

14. An electric system having, in combination, four serially-connectedbinary switching circuits for counting successive decades of impulses inthe sequence:

an indicator comprising a decade of display4 devices for registeringsuccessive counting sequences of the switching circuits from zerothrough nine, the sixth and seventh display devices of the decade ofdisplay devices being normallyundesirably operated respectively upon thedisplay i operation of the eighth and ninth display devices in responseto the counting action of the switching circuits, and athreshold-voltage-operated neon tube connected in circuit with the saidsixth and seventh display device for inhibiting their operation upon thesaid display operation respectively of the eighth and ninth displaydevices.

15. An electric system as claimed in claim 13 and in which the saidsixth and seventh display devices are connected to a common terminal andfrom the common terminal, respectively, to the second and third of thefour switching circuits through similar resistances; the nonlineardevice is connected between the said common terminal and, throughfurther resistance of less value, to the fourth switching circuit; andthe eighth and ninth display devices are connected through resistancegreater than the further resistance but 'less than that of the similarresistances to the fourth switching circuit.

16. An electric system as claimed in claim 15 and in which the relationbetween the said similar resistances, the said further resistance andthe last-named resistance is substantially 2R, R/ 3 and R.

References Cited in the le of this patent UNITED STATES PATENTS YorkSept. 18, 1956 Purcell Dec. 2, 1958 4d 10087, Washington, 1955 (pp.84-86 relied on).

